What to do? A compromised capsule when a toric IOL was planned

 What to do? A compromised capsule when

a toric IOL was planned

EYEWORLD | SEPTEMBER 2023

Precise placement and subsequent stability of a toric IOL are of the utmost

importance for success in correcting astigmatism. Capsule tears can threaten

both factors. So what do you do when a capsule tear occurs during cataract surgery

when you planned to implant a toric IOL? Amandeep Rai, MD, FRCSC, said recognition

is the first step with any case of capsule rent, whether or not a toric IOL is planned.

“Once recognized, the surgeon should try to immediately tamponade the vitreous behind the

compromised capsule with a dispersive viscoelastic device. It is incumbent on the surgeon

to ensure that the anterior chamber remains formed; sudden shallowing may cause the rent

to suddenly enlarge,” Dr. Rai said. “Depending on the stage of the surgery, the surgeon should

attempt to keep all lens material anterior to the rent and remove the cataract with altered fluidics.

Generous use of viscoelastic can help compartmentalize the lens fragments in the anterior

chamber and keep the vitreous posterior. “A surgeon should alter the fluidics by

reducing the flow rate, irrigation pressure, and vacuum,” Dr. Rai continued. “Irrigation and

aspiration may be done manually or at low flow settings. Surgeons should ensure that there is no

vitreous prolapse, and this may be aided by the use of diluted triamcinolone intracamerally. Any

vitreous should be removed using a vitrector, and the surgeon should be vigilant and check

for vitreous regularly through the remainder of the case. Suturing the main wound is suggested,

as this patient may require a vitrectomy and is also at increased risk of postoperative endophthalmitis.

Intracameral antibiotics should also be considered.”

When it comes to IOL selection, Dr. Rai said it depends on capsular support and the type of

rent. If it is an anterior capsule (AC) rent, Dr. Rai said that a single-piece IOL can be placed if

the surgeon is confident in the long-term axial and rotational stability.

“This depends on appropriate placement of the haptics so that a haptic does not tilt

forward; if a single haptic is in the bag and the other haptic tilts forward into the sulcus, the

patient is at high risk for postoperative uveitisglaucoma- hyphema (UGH) syndrome,” he said.

“The tilt can also induce astigmatism and/or coma. The ideal scenario would be a small AC

rent that happens to coincide with the steep axis of corneal astigmatism. This would allow

the physician to orient the toric IOL such that the haptic-optic junction is around the area of

the rent, and both haptics will be entirely secured under the remaining capsulorhexis edge.”

A single-piece IOL may also be an option in the setting of a posterior capsule rupture (PCR),

provided the posterior capsule surface area is large enough to support the IOL long term.

“If the surgeon is able to keep the PCR small and controlled throughout the remainder

of the surgery, a single-piece IOL is certainly a plausible outcome; in that scenario, a toric IOL

should be considered,” he said. “This is especially true if the PCR can be converted to a posterior

continuous curvilinear capsulorhexis. If the PCR is large and the surgeon thinks that the

remaining posterior capsule cannot support an IOL, a common IOL placement is in the sulcus

(with or without optic capture). In this scenario, the surgeon should not place a single-piece toric

IOL in the sulcus due to the increased risk of UGH syndrome. Instead, a three-piece IOL with

PMMA haptics should be used. An alternate option for placement of a single-piece IOL in

the setting of a PCR is reverse optic capture; a single-piece IOL can be placed with the haptics

in the capsular bag and the optic anterior to the capsulorhexis opening. This technique of

reverse optic capture would allow a surgeon to still implant a single-piece toric IOL in a compromised

capsule.”

If capsular support is entirely insufficient  Dr. Rai also mentioned anterior chamber IOLs,

iris-sutured IOLs, scleral-sutured IOLs, and intrascleral haptic fixation as possibilities.

Jonathan Rubenstein, MD, shared his thoughts on what to do when there is a compromised

capsule and a toric IOL was planned. If there is a PC tear, he said you need to make

sure you can visualize the entire extent of the tear to ensure that it won’t tear out, producing

instability. If it’s localized (and ideally round), Dr. Rubenstein said it’s unlikely to tear out,

and thus OK to place a toric IOL, provided the zonules are still good.

“During placement, avoid further extension of the posterior capsule, using OVD to protect

the capsular bag,” he said. Dr. Rubenstein said if it’s not advisable to

place a toric IOL, you can still address astigmatism in the OR. If you’ve planned for it or have a

nomogram and the proper equipment available, you could perform limbal relaxing incisions

(LRIs), he said. He added that he doesn’t think many surgeons are comfortable or have the

equipment/information available to them in the OR to perform this procedure, if they weren’t

already planning for it. Postop management of astigmatism, if a

monofocal IOL was placed due to the compromised capsule, includes glasses, toric contact

lenses, or a refractive procedure, such as corneal refractive surgery, LRIs, astigmatic keratectomy,

and opposite clear corneal incision. Dr. Rubenstein said these are options for patients who had

a three-piece lens in the sulcus or placed with optic capture. He lets these patients stabilize

for 3 months post-cataract surgery because “at that point, it’s refractive astigmatism rather than

astigmatism based on corneal measurement.” The physicians also addressed the patient

counseling aspect of this complication. “The discussion,” Dr. Rubenstein said, “is:

‘Our first priority is to get your cataract out safely and completely, which we were able

to accomplish. … Second, we want to put a lens implant in your eye that is as close to the

correct power and as stable as possible, and we were able to accomplish that. Third is to try to

produce the lowest residual refractive error … as possible, and we’re able to correct hopefully

the spherical part of your refraction, but you still have astigmatism, which we were not able

to correct in surgery, and we will offer you the opportunity to correct that later.’ We’ll say something

like, ‘During surgery we assessed that your eye was not stable enough to support the type

of lens implant that we originally had planned to correct astigmatism; we thought it was unsafe

to use that kind of lens because we couldn’t be assured it would stay in the position that was

needed to fully correct your astigmatism, and therefore we put in a lens implant that does not

correct astigmatism because it was the most stable lens for your eye. We can always come back

later and correct your astigmatism.’” Dr. Rai also said it’s important to thoroughly

discuss this situation with the patient and theirfamily postop, namely because these patients

are at increased risk for complications, such as high intraocular pressure in the first few hours

postop, endophthalmitis in the days postop, and/or retinal tear/detachment, CME, or

pseudophakic bullous keratopathy in the weeks postop.

“They may also need further surgery for retained fragments. As such, patient education

is important so they may seek immediate and appropriate care for any postoperative complications.

These patients should also be scheduled for close follow-up to monitor for complications

and ensure a safe recovery,” Dr. Rai said. Overall, Dr. Rai said that patients with

astigmatism can benefit from a well-placed toric IOL, and even in the setting of some capsular

complications, it is still possible, depending on a few factors, to deliver the best possible uncorrected

distance visual acuity to patients.

A toric IOL on axis, placed after a localized posterior capsular tear

Source (all): Jonathan Rubenstein, MD